An impure sample of solid Na₂CO₃ is allowed to react with 0.1755 M HCl.
[tex]Na_2CO_3 + 2HCl \longrightarrow 2NaCl + CO_2 + H_2O[/tex]
A 0.2337-g sample of sodium carbonate requires 15.55 mL of HCl solution. What is the purity of the sodium carbonate?

Respuesta :

Answer: Thus percentage purity of sodium carbonate is 60.83%.

Explanation:

[tex]Na_2CO_3 + 2HCl \longrightarrow 2NaCl + CO_2 + H_2O[/tex]

Volume of the HCl solution ,V = 15.55 mL= 0.01555 L

Concentration of HCl solution ,C= 0.1755 M

Moles of HCl in 0.1755 M solution = n

[tex]Molarity=\frac{n}{V(L)}[/tex]

[tex]n=C\time V=0.1755 M\times 0.01555 L = 2.729\times 10^{-3} mol[/tex]

According o reaction 2 moles of HCl reacts with 1 mole of sodium carbonate.

Then n moles of HCl will react with:

[tex]\frac{1}{2}\times n=\frac{1}{2}\times 2.729\times 10^{-3} mol=1.3645\times 10^{-3} mol[/tex] of sodium carbonate.

Mass of [tex]1.364\times 10^{-3} mol[/tex] of sodium carbonate:

[tex]1.364\times 10^{-3} mol\times 106 g/mol=0.144584 g[/tex]

Mass of the sample given= 0.2377 grams

Mass used up in reaction = 0.144585 g

percentage purity= [tex]\frac{0.144585}{0.2337}\times 100=60.83\%[/tex]

Thus percentage purity of sodium carbonate is 60.83%.